- hereditary hemochromatosis
- idiopathic hemochromatosis
- bronze diabetes
- iron overload disease
Hemochromatosis is a genetic disorder that affects the way the body handles iron. It causes iron to accumulate in the organs of affected people. The excessive iron causes the symptoms of the disorder.
What is going on in the body?
Everyone absorbs iron from the food they eat. In a person with hemochromatosis, too much iron is absorbed. The iron accumulates in organs such as the liver, heart, and pancreas. The overload of iron, if untreated, can lead to chronic liver disease, liver cancer, congestive heart failure, and diabetes.
What are the causes and risks of the disease?
Hemochromatosis is caused by a defective gene. The gene for hemochromatosis is recessive. This means a person must have two copies of this gene to have the disease.
People with a single copy of the gene are called carriers. Carriers usually are not affected, although use of alcohol may cause symptoms to appear in them. One in twenty people of Caucasian ancestry have the defective gene.
Hemochromatosis is particularly common among the French and among Mormons in the United States.
What can be done to prevent the disease?
Nothing can be done to prevent the defect in iron handling that leads to hemochromatosis. The symptoms can be avoided or minimized by removing blood at regular intervals. Affected people and carriers of the gene should avoid use of alcohol and steroid medications.
Genetic counseling may be useful for couples with a family history of the disease.
How is the disease diagnosed?
Hemochromatosis is diagnosed by measuring the amount of iron in the blood. There are several blood tests that can do this:
- serum ferritin, which measures the protein that acts as a carrier for iron in the blood stream
- serum iron, which measures iron concentrations in the blood
- total iron-binding capacity, or TIBC, which measures the amount of iron that can potentially be stored in the blood
The level of iron compounds in the urine may also be measured. Also, a liver biopsy may be done to obtain tissue for examination in the laboratory. Now that the gene that causes hemochromatosis has been identified, however, DNA testing to examine a person's genes may be done to diagnose the disease.
Long Term Effects
What are the long-term effects of the disease?
Iron overload in a person with hemochromatosis probably starts at birth. The symptoms usually are not obvious, however, until middle life. As the disorder progresses it leads to:
- loss of sex drive, or erectile dysfunction
- congestive heart failure
- irregular heartbeats, or arrhythmias
- joint pains
- sensitivity to cold
What are the risks to others?
Hemochromatosis is not contagious. Parents who have had an affected child are at risk of having other affected children. Because the symptoms come on later in life, affected parents often do not know there is a risk until after their reproductive years. A person with hemochromatosis will pass on defective genes to his or her children. The children will not be affected unless the other parent is affected or carries the gene. However, they will be carriers of the gene. Genetic counseling can be useful in providing additional information for family members.
What are the treatments for the disease?
The most effective treatment for hemochromatosis is to remove blood that is saturated by iron. This can be done through simple blood drawing techniques.
After the blood is withdrawn, the body makes more blood that is not saturated by iron. Over time the newly formed blood becomes saturated and must also be withdrawn.
When hemochromatosis is first recognized, the blood may have to be withdrawn every couple of weeks for 2 to 3 years. Thereafter, it may be withdrawn a couple of times a year.
The blood that is withdrawn usually is discarded.
If removal of saturated blood is not possible, chelation therapy can be used to bind the iron and excrete it in the urine. Deferoxamine (i.e., Desferal) injections, for example, bind up iron and remove it from the bloodstream.
Chelation therapy does not remove nearly as much iron as removing blood from the body. That is why frequent blood draws are the preferred treatment, if at all possible.
If organ damage has already taken place, the resulting conditions such as diabetes, erectile dysfunction, congestive heart failure, and cirrhosis must be treated.
What are the side effects of the treatments?
If only small amounts of blood are withdrawn, there are no side effects of treatment. If too much blood is removed, symptoms of anemia can occur. These can include fatigue, weakness, and shortness of breath. Deferoxamine can cause allergic reactions, skin rash, and diarrhea.
What happens after treatment for the disease?
Treatment for hemochromatosis is a life long process. If treatment is stopped, the blood becomes saturated by iron and symptoms will reappear.
How is the disease monitored?
Hemochromatosis is monitored by checking the level of iron every several months.
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King RA, Rotter JI and Motulsky AG: The Genetic Basis of Common Diseases. Oxford University Press, 1992.
Fauci AS, Braunwald E, Isselbacher KJ, et al, eds. Harrison's Principles of Internal Medicine- Companion Handbook. New York: McGraw-Hill. 1998;980-981.